Childhood cancer survivors represent a large and growing group of survivors who are at increased risk for developing subsequent cancers. Therefore, it is of critical importance that all preventable risk factors be minimized among this population. We have recently completed Partnership for Health (PFH), a peer-delivered telephone-based counseling intervention among childhood cancer survivors. The intervention also included free nicotine replacement therapy (NRT) and tailored and targeted materials. The PFH intervention resulted in a doubling of quit rates in the treatment group compared to a self-help control group. A key issue is now how to disseminate smoking interventions to this population. In order to maximize the dissemination of PFH, we must identify strategies for maintaining the intervention efficacy while making the intervention more widely available at lower cost. The aim of this randomized controlled trial is develop and evaluate the efficacy of a Web-based intervention for smoking cessation among this group, compared to a Materials-only condition. We hypothesize that survivors assigned to the Web-based intervention condition will achieve higher rates of cessation, higher numbers of quit attempts, and greater increases in motivation for smoking cessation. We also anticipate that the Web-based intervention will yield higher reach and impact, and will be more cost-effective than the Materials intervention. This study will make significant contributions toward increasing the reach of a tested intervention. Additionally, this study will make significant steps toward dissemination of tested smoking cessation interventions among cancer survivors.